Kwikee Step… failure and troubleshooting experience

[MandG-Fun]

I am writing this because I had assumed the 2 main points of failure with Kwikee steps being either the controller or the motor was the cause of my step failure. As I will typically do when a system fails that I have no prior experience with, I do some searching in iRV2, which normally turns up someone that had the same problem and their fix. In my case it turned out to not be the motor or controller so I figured sharing my experience may help someone else and I’ll step through the troubleshooting of the controller and motor along the way. By the way, my coach has a Kwikee model 28 single step, although I suspect my experience will apply to most other Kwikee model electric steps.

It goes without saying that you need to use common sense for safety as you’ll either be under the coach or working around the step that has a very strong motor and scissor mechanisms that can do some real damage to body parts.

Mechanical problems never happen at a convenient time… we had just begun a 2 week road trip across the country to visit family and on day 2 the step stopped working, fortunately for driving purposes it was in, not out… which is unfortunate for disassembly purposes. I’ve had a few occasions over the years where the step stopped working and by fiddling with the connectors to essentially clean the contacts it started working again. A little dielectric grease on all connectors is a good practice for all coach connectors. I did as much as I could at our next stop but no luck. Our first stop was to visit a friend who happens to be a carpenter so we whipped up a simple wooden step that we could use for the balance of our trip.

While on the trip, my assumption was the controller had gone bad so I ordered a controller to arrive when we got home. With the step locked in the in position I decided to start with a little troubleshooting. Not wanting to fight to remove and replace the controller box with the step in I just wired in the new controller without actually installing it. With the controller wired in fully the step still did not work.

OK so known good controller… next was to troubleshoot whether I was getting power properly to the controller which would also validate that the magnetic reed switch is working for sensing if the door is open or closed. Fortunately, the Kwikee manual has a very comprehensive electrical troubleshooting section and this manual applies to many different model steps. You can download it from this link or do a search for Kwikee manual 1422279. They recommend having a power test harness but if you get under the coach and disconnect the main power harness you can easily get to the 4 pin connector for testing with your multimeter.

All power tests were good so it must be the motor right? Maybe not... keep reading. With known good power coming to the controller and a known good controller next was to test the motor. In my case not so easy with the step in the locked in position. The steps have seen 20 years of use and the cotter pin on the motor linkage/step clevis pin was all buggered up and when I tried to straighten it as best I could with the limited access restricted by the step it just broke off leaving small bits of the pin protruding from the holes so removing the clevis pin was a project in itself.

In retrospect, while your steps are still working and easy to access with the steps out you may want to consider replacing the 3/32” cotter pin with a clevis spring clip (looks like this) which should make removal much easier if the steps ever lock in the in position. So, clevis pin finally removed and the lower step is now out of the way to remove the motor/gearbox assembly.

To test the motor remove it from the gearbox. I elected to cut the motor power harness off my old controller but leaving enough wire at the controller side to butt splice the cables back on. As you’ll see in the Kwikee manual you can purchase a test harness for the motor too, I'm cheap and impatient so I'm fine with my approach. Applying 12v directly from a battery I had laying around showed that the motor was running fine. Reverse the wires and the motor spun in the opposite direction. OK, the motor is good.

I then started moving the linkage arm on the gearbox by hand and immediately found that it was binding at a certain point in the swing. With a dental tool and paper towels I removed the grease and found that the driven gear teeth had worn at a certain point, I suspect in the out position from continuous wear when stepping on the step. Its a little difficult to see but enough to make it bind and was the obvious reason for the failure (pictures below). The driven gear is held to the linkage arm with a nylok nut at the top of the shaft and a roll pin. Since the driven gear only spins about 60 degrees I figured I would see if I could index the gear 180 degrees to a brand new section. Using a 1/8” pin punch I removed the roll pin, removed the nut and spun the gear... easy peasy, new teeth. The drive gear seemed to be OK so I’m calling this good and saving the money on replacing the gearbox for now. At least I understand how the whole thing comes apart and goes together again. I reassembled the gearbox, greased the gears and reassembled the entire system. To aid in reinserting the clevis pin I had my wife at the main house power disconnect and while opening the door she cut power before the linkage was fully extended. This allowed me to easily reinstall the pin with no tension on the assembly.

One note about step system functionality that had me wondering if I had to figure out how to realign everything to work properly since I had the gearbox apart with no idea of how things were previously aligned. The system doesn’t care where the linkage is positioned relative to the last time it operated. When the door opens or closes, sending power to the motor to move the steps it senses the increase in amperage from the motor when the steps hit the limit of travel and stops sending power to the motor, simple. The steps are now working as they were before and I'm off to my next project... installing a solar charging system.

I hope this is helpful... happy trails!

[Stan&Jacquie]

Nice presentation one the gear fix. As an aside, note that dielectric grease is essentially a non conductor and is not advised for terminal connectors. Motors are very sensitive to voltage drops and dielectric grease can cause one.

[MandG-Fun]

Interesting Stan. I suppose that's the trade off between water getting into the connector and causing corrosion on the contacts. Given the placement of the step connectors they are very water susceptible. Do you have a recommendation of a better material to use to minimize corrosion on the contacts?

[Stan&Jacquie]

I simply try to keep contacts clean . I use dielectric grease for waterproofing but limit its use to terminal connections but not directly on the contacts or the mating surfaces of connectors.

[gofastnow]

I have been fighting mine (32 series) for about 15 years, would infrequently get stuck in the out position. My fix through the years was to kick it a time or two and it would then retract, that was until recently. Mine was stuck solid, so I took the above advice form ManG-Fun and disassembled my gearbox and found the big gear's teeth were also worn. Did ManG's 180 degree rotation trick and I am back up and running, or stepping that is.
I suspect others having similar problem of stuck in a full travel position are suffering from the same problem, as the motor's power is turned off when excess motor current is detected (as opposed to having travel limit switches in place) which occurs at each travel end. Yes, there is no end of travel detection, just current excess draw monitoring. This method of motor power control is also a safety feature so as to not continue if something impedes the steps travel.

THANK YOU ManD-Fun for sharing your smart repair tip!

[RKins]

Originally Posted by MandG-Fun

Interesting Stan. I suppose that's the trade off between water getting into the connector and causing corrosion on the contacts. Given the placement of the step connectors they are very water susceptible. Do you have a recommendation of a better material to use to minimize corrosion on the contacts?

Use conductive grease on the contacts.